NationStates Jolt Archive

http://www.fas.org/nuke/guide/usa/doctrine/dod/fm8-9/tab3-I.gif
From that table, can anyone tell me what the blast radius of a 125 megaton nuclear explosion would be? Apparently the radius doesn't go up by simple multiples.

(1000 kt equals one megaton).

#1 image didnt work
#2 it goes up exponentialy

I put the figures into Excel and calculated a trendline with the equation
y=131.82*x^0.4414

With that equation a 250,000 kt bomb would have a blast radius of nearly 32,000 m.

Without algebrai (which this isn't / it's a logarithmic function), the rule of thumb is blast is relative to the cube of the size of the explosive.

To work this out, a 125MT bomb is 125 x as large as a 1,000KT (1MT) bomb, The cube root of 125 is 5 so the blast of a 125MT bomb will have a radius equal to about 5 times the radius of a 1MT bomb or aproximately 15,500M for blast(50%casualties).

Without algebrai (which this isn't / it's a logarithmic function), the rule of thumb is blast is relative to the cube of the size of the explosive.

To work this out, a 125MT bomb is 125 x as large as a 1,000KT (1MT) bomb, The cube root of 125 is 5 so the blast of a 125MT bomb will have a radius equal to about 5 times the radius of a 1MT bomb or aproximately 15,500M for blast(50%casualties).

Those numbers don't work for the smaller values in the table. The difference between 1 and 1000 kt is 1000, and the cube root of that is 10. But 140 x 10 is not 3100.

Wait, you guys have conflicting answers.

Using excel, I tried the versions they have preprogrammed (linear, log, polynomial, power, exponential) The best was power. The equation is
y = 131.82x^0.4414, where x equal Kt. So 125000 Kt would be 23429 m.

The R^2 for the power is 0.99, linear is 0.98. Log is worse at around 0.8

Hope that helps.

Using excel, I tried the versions they have preprogrammed (linear, log, polynomial, power, exponential) The best was power. The equation is
y = 131.82x^0.4414, where x equal Kt. So 125000 Kt would be 23429 m.

The R^2 for the power is 0.99, linear is 0.98. Log is worse at around 0.8

Hope that helps.Thank you all. I forgot all of that logarithm stuff approximately as soon as I learned it. Or did I learn it in the first place? Probably not. Whatever.

There is a freeware program that you should be able to find on google called "fallout" which allows you to simulate a nuclear explosion up to 200MT. I used it for a physics assignment once.

Edit: Any blast over 250kt will use a different equation and result in different radiation levels as they need to rely on a fusion reaction instead of a fission one.

There is a freeware program that you should be able to find on google called "fallout" which allows you to simulate a nuclear explosion up to 200MT. I used it for a physics assignment once.

Edit: Any blast over 250kt will use a different equation and result in different radiation levels as they need to rely on a fusion reaction instead of a fission one.Do you have a link, because I can't find it?

This may work....

http://wasmerconsulting.com/airrad.htm

ah shit, now im just confused...

There is a freeware program that you should be able to find on google called "fallout" which allows you to simulate a nuclear explosion up to 200MT. I used it for a physics assignment once.

Edit: Any blast over 250kt will use a different equation and result in different radiation levels as they need to rely on a fusion reaction instead of a fission one.Do you have a link, because I can't find it?

I have the .zip file on my computer, but no link unfortunately. I'll look though.

There is a freeware program that you should be able to find on google called "fallout" which allows you to simulate a nuclear explosion up to 200MT. I used it for a physics assignment once.

Edit: Any blast over 250kt will use a different equation and result in different radiation levels as they need to rely on a fusion reaction instead of a fission one.Do you have a link, because I can't find it?

I have the .zip file on my computer, but no link unfortunately. I'll look though.

It's your lucky day.

www.stevequayle.com/News.alert/03_Unrest/Fallout/Fallout.html

Scaling from the 1 MT explosion, it ought to be 15500 m. Explosive radii vary with the cube root of the yield of the new bomb divided by the base yield multiplied by the base blast radius. This doesn't take into account many factors, but from a purely mathematical standpoint it is correct.
It can be written as:

r_2=r_b(y_2/y_b)^1/3